检索结果-南通市图书馆

Shape blending of artistic brushstroke represented by disk B-spline curves

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第12期17卷 1501-1507页

作者： Cheng Min1,2.and Wang Guojin1(1. department of Mathematics, zhejiang university,{2., china 2. department of Mathematics, zhejiang university of Technology, hangzhou 310032. china) department of Mathematics Zhejiang University Hangzhou 310027 China department of Mathematics Zhejiang University of Technology Hangzhou 310032 China

This paper presents an algorithm for automatically generating in-between frames of two artistic brushstrokes. The basic idea of the algorithm is to represent the two key frames of artistic brushstrokes in disk B-spline curves, and then make blending of their geometric intrinsic variables. Given two key frames of artistic brushstrokes, the skeleton curves can be obtained by certain skeleton-based techniques. After disk B-spline representation of the key frames is generated, interpolation of the intrinsic variables of the initial and the target disk B-spline curves is carried out. Examples show that this method can efficiently create in-between frames of artistic brushstrokes.

关键词： computer aided calligraphy shape blending brushstroke disk B-spline curve skeleton.

Low temperature albitization in Caino-Mesozoic reservoir sandstones from North Tarim, and a discussion on the fluid origin

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第S2期44卷 35-37页

作者： YE Ying~1, HU Shouxi~2.and SUN Jinggui~2.1. department of earth {2., zhejiang university, hangzhou 31002., china 2. department of earth sciences, Nanjing university, Nanjing 2.0008, china department of earth {2. Zhejiang University Hangzhou 310027 China department of earth {2. Nanjing University Nanjing 210008 China

CAJNOZOIC and Mesozoic in North Tarim are predominantly a set of terrestrial detrital formations. In thereservoir sandstones in the area, albite is one of the widely developed authigenic mineral. Micro-structural evidence shows that diagenetic albite occurs as euhedral crystals in the pore, and replaces feldsparand other detritus along cleavage and micro-crack. EPMA analyzing found that some of the alteration product has a chemical composition between purealbite and the replaced detrital feldspar. For example, composition of replaced alkali feldspar is betweenmicrocline and albite, and content of altered plagioclase decreases continuously. This has been regardedas direct evidence for fluid replacement, for feldspar crystallized from solution or magma is usually withfixed chemical composition. Taking alkali feldspar as an example, although Kf and Ab forming completeisomorphous admixture in high temperature, they exsolved out as two relative pure phases while temperature decreases.

关键词： low temperature albitization sandstones fluid origin North Tarim.

Online uniform machine covering with the known largest size

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第11期17卷 1271-1278页

作者： Cao Shunjuan1,2.and Tan Zhiyi1,3(1. department of Mathematics, zhejiang university,{2., china 2. department of Mathematics, zhejiang Forestry university, hangzhou 311300, china 3. State Key Laboratory of CAD & CG, zhejiang university,{2., china) department of Mathematics Zhejiang University Hangzhou 310027 China department of Mathematics Zhejiang Forestry University Hangzhou 311300 China State Key Laboratory of CAD & CG Zhejiang University Hangzhou 310027 China

This paper investigates the semi-online scheduling problem with the known largest size on two uniform machines. The objective is to maximize the minimum machine completion time. Both lower bounds and algorithms are given. Algorithms are optimal for the majority values of s≥1, where s is the speed ratio of the two machines. The largest gap between the competitive ratio and the lower bound is about 0.064. Moreover, the overall competitive ratio 2.matches the overall lower bound.

关键词： scheduling and covering uniform machine design and analysis of algorithm online competitive ratio

Electro-mechanical response of functionally graded beams with imperfectly integrated surface piezoelectric layers

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2006年第5期49卷 513-525页

作者： YAN Wei1 & CHEN Weiqiu1,2.1. department of Civil Engineering, zhejiang university,{2., china 2. State Key Lab of CAD & CG, zhejiang university,{2., china department of Civil Engineering Zhejiang University Hangzhou China State Key Lab of CAD & CG Zhejiang University Hangzhou China

The time-dependent behavior of a simply-supported functionally graded beam bonded with piezoelectric sensors and actuators is studied using the state-space method. The creep behavior of bonding adhesives between piezoelectric layers and beam is characterized by a Kelvin-Voigt viscoelastic model, which is practical in a high temperature circumstance. Both the host elastic functionally graded beam and the piezoelectric layers are orthotropic and in a state of plane stress, with the former being inhomogeneous along the thickness direction. A laminate model is employed to approximate the host beam. Moreover, the coupling effect between the elastic deformation and electric field in piezoelectric layers is considered. Results indicate that the viscoelastic property of interfacial adhesives has a significant effect on the function of bonded actuators and sensors with time elapsing.

关键词： functionally graded beam piezoelectric layers Kelvin-Voigt model state-space method

Perturbations of the radical of nest algebras

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第7期43卷 556-560页

作者： LU Fangyan 1 and LU Shijie 2.1. department of Mathematics, Suzhou university, Suzhou 2.5006,{2. 2. department of Mathematics, zhejiang university, hangzhou 31002.,{2. department of Mathematics Suzhou University Suzhou China department of Mathematics Zhejiang University Hangzhou China

Let R N and K-N be the radical ideal and the compact operator ideal of nest algebra T(N) respectively. It is proved thatR-N+K-N=span{T∈T(N)∶TT(N)NCT}=span{T∈T(N): #σ′(ST)≤1, S∈T(N)}.

关键词： nest algebras radical perturbation.

Synthesis and crystal structure of complex of Ce(NO_3)_3 with N-(3-methyl-pyridin-2.yl)-formimidoyl-(3-methyl-pyridin-2.yl) hydrazone

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2004年第3期47卷 251-256页

作者： JIANG Yinzhi1,2.& HU Weixiao1 1. department of Pharmaceutical Science, zhejiang university of Technology, {2. 310032. china 2. department of Applied Chemistry, zhejiang Institute of Science and Technology, {2. 310033, china department of Pharmaceutical Science Zhejiang University of Technology Hangzhou China department of Applied Chemistry Zhejiang Institute of Science and Technology Hangzhou China

The reaction of 3,6-di-(3-methyl-pyridin-2.yI)-s-tetrazine (DMPTZ, II) with CeIII salt [Ce(NO3)3 · 6H2.] generates a new ligand, N-(3-methyl-pyridin-2.yl)-formimidoyl-(3-methyl-pyridin-2.yl) hydrazone (L), and forms a new complex: a mononuclear complex [Ce(L)(NO3)2.(H2.)3] · NO3 (III). Crystal data for III: space group P-1, with a = 0.7133(4) nm, b = 1.1139(2. nm, c = 1.4572.3) nm, α= 102.13(2.°, β= 99.81(3)°, γ= 91.10(3)°, Z = 2. V = 1113.6(7) nm3, μ = 2.12. mm?1 and F(000) = 630. L acts as a tri-dentate chelating ligand in III. There are 10 coordination sites around Ce3+ of III, which are respectively occupied by seven oxygen atoms (four from two nitrate anions and three from three H2. molecules) and three nitrogen atoms (all from L). The cerium atom and three chelating nitrogen atoms are coplanar. The mechanism of the metal assisted decomposition is discussed briefly.

关键词： rare earth, complex, crystal structure, synthesize, 3,6-bis (3-methyl-pyridin-2.yl)-s-tetrazine, N-(3-methyl-pyridin- 2.yl)-formimidoyl-(3-methyl-pyridin-2.yl) hydrazone.

THE CONVERGENCE ON A FAMILY OF ITERATIONS WITH CUBIC ORDER

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2001年第5期19卷 467-474页

作者： Dan-fu Han (department of Mathematics, zhejiang university,{2., china) 浙江大学浙江杭州 310028

Establishes a convergent theorem for a family of iterations with cubic order by using general convergence hypotheses. Disadvantage of using the cubic majorizing function; Convergence of the majorizing sequence; Overvi... 详细信息

关键词： convergence majorizing method gamma-condition error estimate

ON MULTIPLE POSITIVE SOLUTIONS FOR A NONLINEAR ELLIPTIC PROBLEM IN R^N

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2000年第3期21卷 351-358页

作者： YANG HAITAO(department of Mathematics, zhejiang university,{2., china.) WU SHAOPING(department of Mathematics, zhejiang university,{2., china.) department of Mathematics Zhejiang University Hangzhou 310027 China

By making use of Variational method, the authors obtain some results about existence of multiple positive solutions and their asymptotic behavior as the parameter →＋∞ for a semilinear elliptic problem in RN.

关键词： Critical point Asymptotic behavior Concentration

Dynamic behavior of polymer surface and the time dependence of contact angle

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2005年第6期48卷 553-559页

作者： WANG Xinping1, CHEN Zhifang1 & SHEN Zhiquan2.1. Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry, department of Applied Chemistry, zhejiang Institute of Science and Technology, {2. 310033, china 2. department of Polymer Science and Engineering, zhejiang university, hangzhou 31002., china Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry Department of Applied Chemistry Zhejiang Institute of Science and Technology Hangzhou 310033 China

Time-dependent contact angles were measured by depositing sessile drops of wa-ter on the polymer surfaces and monitoring the drop shape as a function of time. It was found that contact angles decreased sharply with contact time and the equilibrium contact angle was finally attained after a certain time. Values of starting (θ s) and equilibrium contact angles (θ e) obtained by the sessile drop method depend on polymer properties. The Wilhelmy plate technique was used to measure advancing and receding contact angles. The variations of starting (θ s) and equilibrium contact angles (θ e), advancing (θ a) and receding contact angles (θ r) have been studied on the oxidized surface of polymers containing polybutadiene block to explore the cause of time-dependence in contact angle measurement and the meaning of θ s and θ e. The results showed the linear relationships between starting (θ s) and advancing contact angles (θ a), the equilibrium (θ e) and receding contact angles (θ r). The similar relationship was also established between the contact angle hysteresis (θ a?θ r) and differences (θ s ?θ e) in starting contact angles and equilibrium contact angles. Therefore, time-dependence in contact angle measurement was mainly attributed to the surface reconstruction when water drops were deposited on polymer surfaces. The starting contact angle was contributed by the hydrophobic component on polymer surface and the equilibrium contact angle mainly by the hydrophilic component of polymer. These results not only demonstrated the interdependency between two contact angle measurements, the sessile drop method and the Wilhelmy plate technique, but also provided the experimental evidence to explain the cause of time-dependent contact angle. This may also provide a new method to study dynamic behavior of polymer surface.

关键词： contact angle, surface dynamic behavior, polymer surface, dynamic contact angle, time-dependence.